Other forms: coups d'etat
If you hear about a foreign government's violent overthrow on the news, you can describe it as a coup d'etat.
The noun coup d'etat is useful for talking about revolutionary uprisings or military takeovers that result in a country's government changing hands very suddenly. The term is often shortened to just coup, and it has been used in English since the late 1700s. Coup d'etat means "stroke of the state," or "strike against the state," and since it's French, it's pronounced "coo day tah."